Colby and Alyssa Hacker's 18-month-old son, Owen, is a very friendly toddler. One of his favorite things to do, in fact, is to tell everyone he sees "hi" and "bye."

Alyssa found herself killing time at Target in Fort Smith, Arkansas, with Owen this weekend while they were visiting her mother-in-law in nearby Wister, Oklahoma. She wasn't surprised, she told TODAY Parents, when her son suddenly yelled out "Hi!" while he was in her cart playing with three stuffed dinosaurs he had spotted in the toy aisle. But what happened next did surprise her.

The only person around them in the aisle was an older gentleman who turned around and addressed Owen directly, Alyssa said. "Hi, sweet boy," he said, and he began playing with the dinosaurs with her son.

Although she is often on guard with strangers, especially around her child, Alyssa said she didn't have any uneasy feelings at that moment with this man. "That's not like me," she said. "I'm always in mommy protective mode, but I know this was a God thing that happened."

After a few moments of playing with Owen, the man pulled out his wallet. "I kind of had a feeling he was going to give Owen money for a dinosaur, but I wasn't expecting what was to come," said Alyssa. The man pulled out a $20 bill and tucked it in the pocket of Owen's shirt, and when he looked at Alyssa, she saw big tears in his eyes.

"I just lost my 2-year-old grandson last week," he told Alyssa. "You take this money and buy this boy all three dinosaurs." Then he walked away.

Alyssa posted about the sweet encounter on her Facebook page in an effort to share something positive with her friends. "Everyone can use a reminder that there are still good people in this crazy, mixed-up world," she said.

She has been shocked by the response to the post, which has now been shared over 105,000 times on Facebook in just a few days. "Owen has been such a blessing to us, and I love being able to share that blessing with others!" she said. "I pray he continues to be that light in someone's day, every single day."

Most importantly, Alyssa did use the $20 to buy Owen all three of the dinosaurs he was so enamored with in the store. "These three stuffed dinosaurs have more meaning than I ever thought a stuffed animal from Target could have," she said. "We will hold on to these memories forever!"